From 60e184fb33d30af47a9f7518ba58ff6c38dc4105 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Tue, 2 Jun 2015 11:26:34 +0200 Subject: [PATCH] ufs: Fix possible deadlock when looking up directories Commit 4b7c6745dad351f8e (ufs: deal with nfsd/iget races) made ufs create inodes with I_NEW flag set. However ufs_mkdir() never cleared this flag. Thus if someone ever tried to lookup the directory by inode number, he would deadlock waiting for I_NEW to be cleared. Luckily this mostly happens only if the filesystem is exported over NFS since otherwise we have the inode attached to dentry and don't look it up by inode number. In rare cases dentry can get freed without inode being freed and then we'd hit the deadlock even without NFS export. Fix the problem by clearing I_NEW before instantiating new directory inode. Fixes: 4b7c6745dad351f8ed310f6e0e7972a4760d49a9 Reported-by: Fabian Frederick Signed-off-by: Jan Kara Signed-off-by: Al Viro --- fs/ufs/namei.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/ufs/namei.c b/fs/ufs/namei.c index 2346b83fa12ba..60ee32249b726 100644 --- a/fs/ufs/namei.c +++ b/fs/ufs/namei.c @@ -212,6 +212,7 @@ static int ufs_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode) goto out_fail; unlock_ufs(dir->i_sb); + unlock_new_inode(inode); d_instantiate(dentry, inode); out: return err; -- 2.39.5